Phenol derivative glycosides are conventionally used as pigments, sweeteners, analgesics, antioxidants, and the like, and are also used as an ingredient for cosmetics for exhibiting an excellent whitening effect. It is known that glycosylation of a phenol derivative can improve the stability, quality of taste and absorbability of the unglycosylated compound.
The present applicant has provided a method for producing a polyphenol glycoside using saccharifying α-amylase (Japanese Patent No. 2662667 and Japanese Patent No. 2805273) produced by Bacillus subtilis strain X-23.
It is also known that a saccharifying amylase not having cyclodextrin synthesizing capability glycosylates polyphenol (Japanese Publication for Opposition No. 7-36758 and J. Ferment. Bioeng., 78:31(1994)). However, When hydroquinone, which is a type of polyphenol, is glycosylated using the conventionally known saccharifying amylase not having cyclodextrin synthesizing capability (Japanese Publication for Opposition No. 7-36758), two glycosides are produced, i.e., hydroquinone-O-α-D-glucopyranoside and hydroquinone-O-α-D-maltoside. The weights of these produced substances are 110 mg and 51 mg, respectively. Thus, conventional methods produce a mixture containing a number of various types of hydroquinone glycosides, causing a problem that the methods require costly purification of a product of interest.
It has been known that some saccharifying amylase derived from Bacillus subtilis has cyclodextrin synthesizing capability (J. Ferment. Bioeng., 81:26(1996)). However, it has never been known that the amylase having cyclodextrin synthesizing capability of Bacillus subtilis can also glycosylate a phenol derivative.
It has also never been known that neopullulanase, cyclomaltodextrinase, and maltogenic α-amylase can transfer a saccharide to a polyphenol to produce a glycoside.
Another conventionally known glycosylation method is a glycosylation method using cyclodextrin glucanotransferase (Japanese Laid-Open Publication No. 3-7593) which transfers an additional saccharide to a saccharide portion of a polyphenol compound containing a saccharide in the molecule. However, this method cannot efficiently transfer a saccharide to a polyphenol compound not containing a saccharide moiety. A number of phenol derivatives having various physiological activities do not contain a saccharide moiety. There is a demand for an improvement in the stability and absorbability of such phenol derivatives.
In a number of enzyme reactions for producing a glycoside, malto-oligosaccharides, which are obtained as byproducts by the end of the enzyme reaction, have no useful application. Therefore, there is a demand for a phenol derivative glycosylation method which produces a useful byproduct.
Conventionally, ligand exchange chromatography using cation exchange resin is used for separation of saccharides, such as separation of glucose and fructose. In chromatography for purifying glycosides, hydrophobic adsorption resin is generally used.